During bone marrow aspiration, a needle is injected into the cancellous bone. A syringe is connected to the needle to aspirate the bone marrow. It is known that the first rapid forceful pull of the syringe plunger is essential to the quality of bone marrow aspirate. However, different operators may apply different pulling force to the plunger and therefore inconsistent bone marrow aspiration is a concern. Aspirating bone marrow from the iliac crest using small volumes of 1-4 ml has been historically proposed for harvesting adult mesenchymal stem cells and described as a standard technique to avoid blood dilution. Studies have shown that bone marrow aspiration using a larger volume syringe (50 ml) as compared with a smaller volume syringe (10 ml) results in a reduced mesenchymal stem cell count in bone marrow aspirates. Recent studies have demonstrated that mesenchymal stem cells are pericytes, i.e., cells that have attachment to the vasculature. In order to release these cells repeated rapid application of pressure is required as opposed to steady pressure. The current invention provides an apparatus that applies a rapid pulling force to the plunger, reducing user variances while also allowing for a more consistent quality of aspirated bone marrow by maximizing mesenchymal stem cell content.